Conventional display panels such as an LCD display panel with backlight illumination use a multi-lamp cold cathode fluorescent system. The light intensity of the backlight illumination is controlled by pulse-width modulation (PWM) of the lamp supply current. Modulating the light intensity in all lamps concurrently results in constant electromagnetic interference (EMI) emission irrespective of light intensity. The peak to average current ratio is also high, which translates into a higher cost system power supply.